1. Field of the Invention
The present invention relates to an ON/OFF valve and, more particularly to an ON/OFF valve capable of drawing back fluid which has passed through the valve, when the valve is closed. Such a valve can be used for a paint valve of a coating apparatus to prevent paint from dripping from a paint nozzle after paint injection through the paint nozzle has stopped.
2. Description of the Related Art
To develop a multi-color coating apparatus provided with a plurality of paint nozzles corresponding to respective paint colors, dripping paint from a paint nozzle must be prevented to prevent paint colors from mixing when paint injection through the paint nozzle has stopped and paint injection through another paint nozzle is started, to change the paint color. If a conventional ON/OFF valve is applied to such a multi-coating apparatus with a plurality of paint nozzles, paint dripping from a paint nozzle after valve closure cannot be completely prevented, because paint fills the entire paint passage from the valve to the tip of the paint nozzle and paint located in the vicinity of the tip of the paint nozzle easily drips from the paint nozzle due to gravity.